A touch panel is an input device that enables a user to directly input a command by selecting command contents displayed on a screen of an image display and the like with a finger or with an object, and when the user is in direct contact with the touch panel with a finger or with the object, the touch panel detects a touch point and drives a liquid crystal display device according to the command of a selected icon to realize specific displaying.
Present touch panels are mainly divided into capacitive touch panels and electromagnetic touch panels according to different working principles: the capacitive touch panels identify touch operations through received touch signals (i.e., electric signals), and the electromagnetic touch panels identify touch operations through received touch signals (i.e., electromagnetic signals from electromagnetic needles). At present, an independent capacitive touch panel is generally assembled on the outer side (i.e., the side facing a viewer) of a liquid crystal display, so as to receive electric signals corresponding to the touch operations; and an independent electromagnetic touch panel is assembled on the outer side of a liquid crystal display or the back of a backlight module.
However, the conventional independent capacitive touch panels and independent electromagnetic touch panels are externally mounted on the liquid crystal display devices, so that the liquid crystal display devices with capacitive and electromagnetic touch functions are relatively thick and relatively complex to be manufactured.